地氟醚、七氟醚和异氟醚对犬冠脉血流的影响

目的：采用超声血流量监测仪观察地氟醚、七氟醚和异氟醚对犬冠脉血流的影响。方法：犬１８只，腹腔注射１．５％硫喷妥钠２０ｍｇ／ｋｇ，静脉注射阿曲库铵０．８ｍｇ／ｋｇ麻醉诱导，气管插管后取正中开胸，分离冠状动脉左前降支，将３ｍｍ或３．５ｍｍ超声Ｄｏｐｐｌｅｒ血管探头置于分离血管处，连接超声多普勒冠脉血流量监测仪测定冠脉血流量，然后随机吸入地氟醚、七氟醚或异氟醚，ＭＡＣ分别为７．２％、２．３％和１．２８％     

地氟醚、异氟醚和七氟醚对脑血流速率的影响

目的　通过经颅多普勒超声 (TCD)监测大脑中动脉 (MCA)血流速率 ,观察地氟醚、异氟醚和七氟醚三种吸入麻醉药对平均血流速率 (Vm)的影响。方法　 42例 18～ 6 0岁、ASAⅠ～Ⅱ级、择期非颅脑手术病人 ,随机接受地氟醚、异氟醚或七氟醚吸入麻醉。机械通气维持PETCO2 在 40± 1mmHg。当呼气末吸入麻醉药浓度分别为 :1 0MAC平衡 15分钟后 ,快速 (2分钟内 )从 1 0MAC升高至 1 5MAC即时 ,1 5MAC平衡 15分钟后 ,以及稳定于 1 5MAC并且维持和 1 0MAC平衡下相似的MAP时 ,记录Vm、MAP和心率。结果　 (1)吸入浓度从 1 0MAC上升至 1 5MAC ,且MAP维持相同水平的情况下 ,地氟醚和异氟醚使Vm增加非常显著 (分别从 5 6cm/s上升至 6 1cm/s,从47cm/s上升至 5 2cm/s,P <0 0 1) ,而七氟醚无显著变化 (从 6 0cm/s至 6 0cm/s,P >0 0 5 )。 (2 )当吸入浓度快速从 1 0MAC上升至 1 5MAC时 ,地氟醚使血压升高、心率增快 ,同时 ,脑血流速率显著增加 (从 5 6cm/s上升至 6 1cm/s,P <0 0 1)。而异氟醚和七氟醚在MAP显著下降的同时使Vm无显著变化 (从 47cm/s升至 49cm/s,P >0 0 5 ) ,或显著下降 (从 6 0cm/s降至 5 6cm/s,P <0 0 1)。结论　 (1)吸入浓度从 1 0MAC增加到 1 5MCA时 ,地氟醚、异氟醚使脑血流速率显著增加 ,而七氟醚作     

地氟醚与七氟醚对颅脑肿瘤手术患者血糖和乳酸的影响

目的研究地氟醚与七氟醚对颅脑肿瘤手术患者血糖和乳酸的影响。方法选择择期行颅脑肿瘤切除的患者64例,年龄21～62岁,ASA分级Ⅰ～Ⅱ级,体质指数20～25 kg/m2,采用随机数字表法分为地氟醚组(Group Des,n=30)与七氟醚组(Group Sevo,n=34),分别采用地氟醚、七氟醚吸入麻醉。分别于手术前(T0)、手术1小时(T1)、手术2小时(T2)、手术结束(T3)取动脉血1 m L,检测血糖和乳酸水平。结果两组患者血糖均升高,在四个不同时间点的比较差异有统计学意义(P0.01);各组在各时间点的比较无统计学意义(P0.05)。两组患者乳酸无明显升高,在各时间点的比较无统计学意义(P0.05);各组在各时间点的比较无统计学意义(P0.05)。结论地氟醚与七氟醚麻醉均增加颅脑肿瘤患者血糖水平。     

低流量吸入地氟醚或异氟醚控制性降压对患儿压力反射敏感性的影响

目的 评价低流量吸入地氟醚或异氟醚控制性降压对患儿压力反射敏感性（BRS）的影响。方法 30例脊柱侧凸女性患儿，ASAⅠ或Ⅱ级，随机分为地氟醚组（D组）和异氟醚组（Ⅰ组）（n=15）。采用低流量吸入技术，逐渐增大吸入浓度使平均动脉压（MAP）控制在55～65mmHg。分别在诱导前（L）、气管插管后即刻（T1）、呼气末麻醉药浓度达到1MAC即刻（T2）、体位改为俯卧位后即刻（L）、血压达到目标值范围30min时（T4）测定心血管BRS。结果 与R相比，两组患儿其余各时点BRS均降低（P〈0．05）；与T1相比，两组患儿T1、T，BRS增高（P〈0．05）；与T2比较，两组患儿T3BRS差异无统计学意义（P〉0．05），T4BRS降低（P〈0．05）；与T3比较，两组患儿T4BRS降低（P〈0．05）；D组患儿改变体位后达到目标血压的时间短于Ⅰ组（P〈0．01）。结论 低流量吸入地氟醚或异氟醚控制性降压可剂量依赖性的抑制患儿BRS，安全有效地实施控制性降压。     

七氟醚对人大脑中动脉血液流速的影响

七氟醚对人脑血流有何影响 ?这是临床医生十分关心的问题。既往报道多为动物实验。我们采用多普勒超声测定的方法 ,研究了七氟醚在不同情况下对人脑血液流速的影响 ,现报道如下。资料与方法一般资料　 12例普外择期手术病人 ,男 7例 ,女 5例 ,年龄 5 3± 4岁 ,体重 60 7± 6 7ｋｇ。术前检查无明显呼吸、循环及中枢神经系统疾患 ,胸透、ＥＣＧ、Ｈｂ、肝、肾功能及水电解质检查均无明显异常。监测方法　病人入室前 3 0分钟肌注哌替啶 5 0ｍｇ、阿托品 0 5ｍｇ。入室后 ,常规测定ＨＲ、ＢＰ、ＳｐＯ2 和ＥＣＧ。按常规将多普勒探头放置在双…     

地氟醚与七氟醚麻醉对老年病人术后认知功能的影响

目的 探讨地氟醚及七氟醚复合麻醉对老年病人术后认知功能恢复的影响。方法 70例择期行全膝或全髋关节置换术的病人,年龄均在65岁以上。静注芬太尼、异丙酚、琥珀胆碱快速诱导插管后随机分为地氟醚和异氟醚组。麻醉诱导前及手术后1、3、6及24h应用Mini-Mental State（MMS）测试方法评定其认知功能。结果 与术前相比,两组病人术后1h MMS值均明显降低。地氟醚组由29.5±0.5降至27.8±1.7;七氟醚组由29.2±1.0降至27.4±1.7。其中85％以上病人术后3h MMS恢复至术前水平。两组病人术前及术后1、3、6及24h MMS比较均无显著差异。结论 老年病人应用地氟醚或七氟醚麻醉,其术后认知功能恢复相似,仅有一过性认知障碍。     

地氟醚和安氟醚麻醉对心肌酶的影响

地氟醚是一种新吸入麻醉药物 ,已应用于临床各科手术的麻醉。但从酶学方面来了解地氟醚对心肌影响的研究较少。本文旨在研究常规手术患者在吸入地氟醚麻醉下血清心肌酶 [肌酸激酶(ＣＫ)、肌酸激酶同工酶 (ＣＫＭＢ)、乳酸脱氢酶 (ＬＤＨ)、羟基丁酸脱氢酶 (ＨＢＯＨ) ]的变化 ,并与吸入安氟醚麻醉下血心肌酶变化进行比较。资料和方法30例患者随机分成 2组。地氟醚组(Ｄ) 15例 :男 7例 ,女 8例 ,平均年龄46 2 6岁 ,普通外科手术 9例 ,妇科手术 6例 ;安氟醚组 (Ａ) 15例 ,男 9例 ,女 6例 ,平均年龄 42 33岁 ,普通外科手术 8例 ,妇科手术 5例…     

地氟醚对全麻病人血氟、尿氟及肾功能的影响

目的观察全麻病人吸入地氟醚后血氟、尿氟、血肌酐(Cr)及尿素氮(BUN)的变化.方法选择择期手术ASAI级病人20例,术前肝肾功能检查均正常.用芬太尼、异丙酚、维库溴铵静注诱导,插管后吸入地氟醚.于吸入地氟醚前、术毕、术后4h、24h、72h、144h采动脉血和静脉血,同时留置尿液,用氟离子选择电极法测定血氟、尿氟的含量.结果地氟醚的麻醉时间为(4.36±0.39)h,吸入浓度为(1.65±0.16)MAC,吸入总量为(7.19±0.82)MAC-h,病人术毕、术后4h、24h、72h、144h的血氟离子浓度及尿氟离子排泄率与吸入前相比均无显著差异,血Cr及BUN含量在各个时间点亦无明显变化.结论地氟醚麻醉后对血氟、尿氟均无明显影响,对肾功能无损害.     

地氟醚、七氟醚和异氟醚对内源性一氧化氮的影响

目的：观察犬吸入地氟醚、七氟醚和异氟醚后血浆ＮＯ含量的变化，以进一步探讨ＮＯ在囱族吸入麻醉药扩血管作用中的地位。方法：犬麻醉后３０分钟，随机吸入地氟醚、一氟醚或异氟醚（ＭＡＣ ７．２％￣２．３％和１．２８％）使呼气末浓度达１ＭＡＣ，持续３０分钟。分别于呼气末浓度达１ＭＡＣ后５分钟、１５分钟和３０分钟和停吸后３０分钟分钟和１２０分钟抽取静脉血，用硝酸盐还原酶法测定ＮＯ。结果：ＮＯ水平在三组药物吸入过     

地氟醚与异氟醚在胸外科手术中麻醉效果的比较

地氟醚（Ｄｅｓｆｌｕｒａｎｅ）是一种新型卤族氟类吸入麻醉药,与异氟醚的化学结构相似,但是其理化性质和生物性质更稳定,血／气分配系数０．４２,本文就其在胸外科手术中的应用效果和异氟谜相比较。资料与方法（１）选择４０例胸外科择期手术患者（食管癌和贲门癌）ＡＳＡⅠ～Ⅱ级,随机分为两组,Ａ组２０例（男１２例,女８例）Ｂ组２０例（男１３例,女７例）,患者均无其它系统严重并发症,两组患者情况均无显著性差异（Ｐ＞０．０５）。（２）方法：两组病人均于术前半小时深部肌注安定１０ｍｇ、阿托品０．５ｍｇ,入室后以１０…     

Physical exercise increases middle cerebral artery blood flow velocity

The effect on the middle cerebral artery blood flow velocity (V_MCA) of moderate and hard physical exercise on an ergometer cycle was examined in 10 healthy volunteers using transcranial Doppler sonography (TCD). During exercise, the heart rate increased by 136% and the systolic blood pressure by 37% (mean values). During initial moderate exercise, V_MCA increased by 51%; in a following period of maximal physical work, V_MCA decreased again by 20% in 9 of 10 volunteers although the heart rate continued to increase by 10% and the systolic blood pressure by 5% (mean values).Constriction of the MCA may explain the initial increase of V_MCA, suggesting a role for large cerebral arteries in autoregulation. Our data indicate that the subsequent decrease of V_MCA is caused by arteriolar constriction, a likely cause of which was hyperventilation during the excessive work period.     

Effect of remifentanil on intracranial pressure and cerebral blood flow velocity in patients with head trauma

BACKGROUND: Remifentanil, an ultra-short-acting opioid, is used as an on-top analgesic in head trauma patients during transient painful procedures, e.g. endotracheal suctioning, physiotherapy, on the intensive care unit. However, previous studies have shown that opioids may increase intracranial pressure and decrease cerebral blood flow. METHODS: The present study investigates the effect of remifentanil on mean arterial blood pressure, intracranial pressure measured with intraparenchymal or epidural probes, and on cerebral blood flow velocity assessed by transcranial Doppler flowmetry in 20 head trauma patients sedated with propofol and sufentanil. Ventilation was adjusted for a target PaCO2 of 4.7-5.1 kPa. After baseline measurements a bolus of remifentanil (0.5 microg x kg(-1) i.v.) was administrated followed by a continuous infusion of remifentanil (0.25 microg x kg(-1) x min(-1) i.v.) for 20 min. RESULTS: There was no change in mean arterial blood pressure, intracranial pressure, and cerebral blood flow velocity in response to remifentanil infusion over time. Statistical analysis was performed using the Wilcoxon Signed Rank test. CONCLUSIONS: These data suggest that remifentanil can be used for on-top analgesia in head trauma patients without adverse effects on cerebrovascular haemodynamics, cerebral perfusion pressure or intracranial pressure.     

应用SPECT研究地氟醚麻醉对人脑血流分布的影响

目的研究吸入不同浓度地氟醚麻醉下健康志愿者脑血流(CBF)分布的动态变化。方法选择9名志愿者,每位志愿者分别在清醒、吸入0.5和1.0MAC地氟醚后采用单光子发射计算机断层成像(SPECT)仪进行扫描,观察地氟醚麻醉下人局部脑血流(rCBF)的动态变化。结果全脑CBF计数在清醒时为127.5±23.1,吸入0.5MAC地氟醚麻醉后全脑CBF计数为130.8±25.4,吸入1.0MAC地氟醚后为128.8±22.9,三组间比较差异无显著意义;额叶、顶叶、颞叶、枕叶、中脑、小脑、丘脑、海马、基底核、扣带回和舌回等脑区rCBF计数差异也均无显著意义。结论在保持PETCO2和MAP稳定且在正常范围时,吸入地氟醚麻醉不影响人脑内血流量的分布。     

腹腔镜手术中对大脑中动脉血流的影响

目的：观察腹腔镜胆囊切除术对病人大脑中动脉血流的影响。方法：采用TCD检测19例全麻病人在气腹前、气腹时和气腹后的平均血流速度（ Vm）、脉动指数（PI）和无创伤动脉血压。结果：各时期Vm无明显变化；PI在气腹时期明显增高，气腹后恢复正常；动脉收缩压和舒张压在气腹时增高，舒张压在气腹后仍高于气腹前水平。结论：腹腔镜胆囊切除术中CO2气腹可通过CO2吸收入血而使脑血管阻力有一定程度的改变，但只要PaCO2维持在正常范围，CO2对脑血流的影响不大。     

Rat model of spinal cord injury preserving dura mater integrity and allowing measurements of cerebrospinal fluid pressure and spinal cord blood flow

Purposes

Cerebrospinal fluid (CSF) pressure elevation may worsen spinal cord ischaemia after spinal cord injury (SCI). We developed a rat model to investigate relationships between CSF pressure and spinal cord blood flow (SCBF).

Methods

Male Wistar rats had SCI induced at Th10 (n = 7) or a sham operation (n = 10). SCBF was measured using laser-Doppler and CSF pressure via a sacral catheter. Dural integrity was assessed using subdural methylene-blue injection (n = 5) and myelography (n = 5).

Results

The SCI group had significantly lower SCBF (p < 0.0001) and higher CSF pressure (p < 0.0001) values compared to the sham-operated group. Sixty minutes after SCI or sham operation, CSF pressure was 8.6 ± 0.4 mmHg in the SCI group versus 5.5 ± 0.5 mmHg in the sham-operated group. No dural tears were found after SCI.

Conclusion

Our rat model allows SCBF and CSF pressure measurements after induced SCI. After SCI, CSF pressure significantly increases.     

机械通气对室间隔缺损患儿脑氧合和脑血流速度的影响

目的探讨麻醉诱导期间机械通气变化对室间隔缺损(ventricular septal defect, VSD)修补术患儿区域脑组织氧饱和度(regional cerebral oxygen saturation, rScO_2)和大脑中动脉血流速度(cerebral blood flow velocity, CBFV)的影响。方法选择VSD修补术患儿67例,男34例,女33例,年龄1岁,体重3.4～11.0 kg,ASAⅡ或Ⅲ级。入室麻醉诱导后气管插管,调整通气参数使P_(ET)CO_2初始值为30 mmHg(T_(30))。持续使用Fore-Sight实时监测右侧额部rScO_2,TCD间断测量CBFV_(收缩期)、CBFV_(舒张期)、CBFV_(平均值)。通过调整通气参数使P_(ET)CO_2逐渐上升至35 mmHg(T_(35))、40 mmHg(T_(40))、45 mmHg(T_(45)),记录对应的CBFV值以及rScO_2,计算每分钟通气量(MV)和T_(30)—T_(35)、T_(35)—T_(40)、T_(40)—T_(45)三个时段的脑血管CO_2反应性(CO_2R)。结果 T_(30)—T_(45)时rScO_2、CBFV_(收缩期)、CBFV_(舒张期)、CBFV_(平均值)均明显增大(P0.01),PI、RI均明显减小(P0.01)。T_(35)—T_(40)时CO_2R在最高值。结论室间隔缺损患儿在麻醉诱导阶段,机械通气对脑氧合和大脑中动脉脑血流速度有明显影响,正常低通气能明显增加脑氧合和脑血流速度。     

Continuous recording of middle cerebral artery blood velocity in clinical neurosurgery

Summary Intracranial pressure, arterial blood pressure, and middle cerebral artery blood velocity were monitored for periods from 1 to 10 days in 30 neurosurgical intensive care patients. The recordings revealed rapid changes in the cerebral perfusion and gave insight into individual cerebral haemodynamic states.Twenty patients consistently showed CO₂ reactivity within normal limits, between 2.5 and 5% per mm Hg (19–38% per kPa). Severely impaired CO₂ reactivity, considerably below 1% per mm Hg (7.5% per kPa) was observed in four patients. Three of these patients died, while the fourth patient survived in a persistent vegetative state.Seven patients demonstrated pressure-passive blood velocity changes throughout the observed CPP range. The four patients with severely impaired CO₂ reactivity all belonged to this group. The recordings from three of the remaining 23 patients showed signs of MCA blood velocity autoregulation with a lower regulatory limit of about 40–45 mm Hg. This observation is in keeping with findings from electromagnetic flowmetry on brain arteries in the neurosurgical operating field, and supports blood velocity measurements as a relevant index of brain perfusion in clinical neurosurgery and neuro-intensive care settings.     

The effect of sevoflurane on cerebral blood flow velocity in children

BACKGROUND: Sevoflurane is a suitable agent for neuroanesthesia in adult patients. In children, cerebrovascular carbon dioxide reactivity is maintained during hypo- and normocapnia under sevoflurane anesthesia. To determine the effects of sevoflurane on middle cerebral artery blood flow velocity (Vmca) in neurologically normal children, Vmca was measured both at different MAC values and at one MAC over a specified time period, using transcranial Doppler sonography. METHODS: Twenty-six healthy children undergoing elective urological surgery were enrolled (16 patients in part I and 10 in part II). In part I of the study anesthesia comprised sevoflurane 0.5, 1.0 and 1.5 MAC in 30% oxygen and a caudal epidural block. Once steady state had been reached at each sevoflurane MAC level, three measurements of Vmca, mean arterial pressure (MAP) and heart rate (HR) were recorded. In part II of the study patients received sevoflurane 1.0 MAC over a 90-min period, with the same variables being recorded at 15-min intervals. RESULTS: Vmca did not vary significantly at 0.5, 1.0 and 1.5 MAC sevoflurane. There was a significant decrease in MAP between 0.5 MAC and 1.0 MAC sevoflurane (P < 0.005) and also between 1.0 MAC and 1.5 MAC (P < 0.01). There was no significant change in Vmca over 90 min at 1.0 MAC sevoflurane. CONCLUSION: Sevoflurane does not significantly affect cerebral blood flow velocity in healthy children at working concentrations.     

Effect of acetazolamide on cerebral artery blood velocity and regional cerebral blood flow in normal subjects

Summary The effect of intravenous acetazolamide L g on cerebral artery blood velocity and regional blood flow (rCBF) was investigated in eight normal subjects. Blood velocity was measured with 2 MHz pulsed Doppler in the proximal segments of the middle, anterior and posterior cerebral artery (MCA, ACA, and PCA) and in the distal extracranial internal carotid artery (ICA). The rCBF in the regions of interest tentatively corresponding to the perfusion territories of these vessels was estimated using¹³³Xe inhalation and a rapidly rotating single photon emission computer tomograph.Both blood velocity and rCBF increased after acetazolamide. There was no significant difference between the percentage ICA blood velocity increase (22 ± 12%) and the percentage rCBF increase in the ICA region of interest (25 ± 9%). In the MCA, ACA, and PCA, however, blood velocity increased more (mean increase 36–42%) than the rCBF in the corresponding regions of interest (mean increase 24–26%). These differences were highly significant suggesting a direct and site specific effect of acetazolamide in narrowing the lumen of the proximal MCA, ACA, and PCA, but not of the extracranial ICA. We also propose that the effect of acetazolamide induces reciprocal changes in the extent of adjacent perfusion territories in individual brain hemispheres.Data compiled from all subjects investigated at two very different perfusion levels (before and after acetazolamide) revealed a significant positive correlation between blood velocity and rCBF.